DESTDIR support , patch taken from the Debian package

by Samuel Hocevar < sam == at == zoy == dot == org >

Originally committed as revision 4651 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1276,10 +1276,10 @@ echo "# Automatically generated by configure - do not modify!" > config.mak
 echo "/* Automatically generated by configure - do not modify! */" > $TMPH
 echo "#define FFMPEG_CONFIGURATION "'"'"$FFMPEG_CONFIGURATION"'"' >> $TMPH
 
-echo "prefix=$prefix" >> config.mak
-echo "libdir=$libdir" >> config.mak
-echo "bindir=$bindir" >> config.mak
-echo "mandir=$mandir" >> config.mak
+echo "prefix=\$(DESTDIR)$prefix" >> config.mak
+echo "libdir=\$(DESTDIR)$libdir" >> config.mak
+echo "bindir=\$(DESTDIR)$bindir" >> config.mak
+echo "mandir=\$(DESTDIR)$mandir" >> config.mak
 echo "MAKE=$make" >> config.mak
 echo "CC=$cc" >> config.mak
 echo "AR=$ar" >> config.mak